A kernel extension is configured to intercept a call to associate a socket with a port of a node in a network. The call originates from a kernel of the node. The kernel extension is configured to determine the port from the call. The kernel extension is configured to determine that the port is one of a plurality of ports for which the node has authority to modify firewall rules of a firewall of the network. The kernel extension is configured to modify firewall rules maintained by the firewall to allow communications for the port to the node through the firewall.